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Dana 300 Ultra-Short HD Rear Output Assembly

Novak's #300RX tailhousing assembly solves key challenges seen by Dana 300 owners. While the 300 is nearly the perfect OEM transfer case, it has its shortcomings - most of them focused in their original tailshaft & tailhousing area.

Dana 300 heavy duty tailshaft

Kit 300RX, tailhousing assembly, Jeep Dana 300, Heavy duty 32-spline, extra short

Kit contents:

  • Shaft, output, 32 spline
  • Tailhousing, cast & machined
  • Bearings, tapered roller
  • Cup, bearing races
  • Seal
  • Drive flange
  • Fittings, breather and plugs
  • Reluctor ring
  • Shims
  • Bushing, pilot
  • Fastening hardware
  • Instructions

This kit comes largely pre-assembled and includes the 32 spline output shaft, tailhousing, opposed tapered roller bearings and cups, seal, drive flange, drive flange nut, reluctor ring, breather fitting, port plug, shims, and pilot bearing. The speed sensor is not included. See Speed Sensors below.

The Dana 300 is reknown for its strength, gearing and operation. But it has a flaw: its 26 spline factory output shaft, which is regarded as its weak link. Additionally, the Dana 300's length and driveshaft u-joint angles (especially 1981-1986 versions) are a problem in many short-wheelbase Jeeps. It is not uncommon for suspension-lifted Jeeps with OEM style transfer cases to experience driveshaft vibrations, strain and even breakage due to excessive u-joint angles.

Novak's 300RX ultra-short HD tailhousing assembly succeeds at solving the above problems with a track record of years in testing.

Super short, heavy duty output assembly

Features

  • Universal companion flange to fit a variety of u-joint and driveshaft styles
  • Hardened alloy shaft, featuring 32 splines
  • Massive, dual, tapered roller bearings
  • A terrifically stable bearing-on-yoke design for long wear and vibration minimization
  • Innovative removal of stress risers and cross-section material maximization in the output shaft
  • Dual, spiraled and funneled oil pickup / drain ports with a generous oiling cavity for outstanding bearing lubrication and cooling
  • Input shaft pilot bearing is grooved with a dual helix for active oil pumping in both forward and reverse operation
  • The output shaft is machined and specially heat-treated for strength and case hardness
  • The tailhousing is cast from 356 aluminum then strengthened and hardened to a T6 condition
    • Broken Dana output shaft
    The factory output shafts are strong, but 26 splines just doesn't cut it for Jeeps seeing greater strains due to tire size, terrain difficulty, Jeep weight and power. .

    Applications & Compatibility

    Compatible Jeeps

    Any Jeep that came factory with a Dana 300, or which has had one succesesfully transplanted into can be compatible with the #300RX kit. And because it shortens the Dana 300, even shorter CJ5's may be compatible - powertrain length depending.

    Compatible Transfer Cases

    The 300RX is compatible with all versions of Dana 300 transfer cases, including the 1980 Jeep version, 1981-1986 version, and the IH Dana 300 equally well. This assembly also works with all known factory and aftermarket gearsets. It is compatible with all known factory and aftermarket transmissions and adaptations.

    Flipped Dana 300 orientations are also compatible with the 300RX as dual breather ports are available.

    This kit is compatible with the 1980 IH Dana 300, in addition to all Jeep versions of the 300.

    1981-1986 long tailhousing version Novak 300RX assembly

    The most common factory (1981-1986) version of the Dana 300 (left) vs. the Novak 300RX version, making for the shortest Dana 300 on the planet.

    For comparison, the following measurements are from the rear face of the transfer case to the center of the universal joint:

    • Stock long output 6.425"
    • Stock short output 5.375"
    • 300RX 4.625"; 1.8" shorter than the long output version and 0.75" shorter than the short output version
    Assembled 300RX to Dana 300
    The breather port can be located upwards in either orientation; conventional passenger's side drop or "flipped" driver's side drop. Breather tubing is not included.

    Installation Requirements

    • Removal of the transfer case from the Jeep
    • Removal of the intermediate shaft and its gear
    • Removal of the input shaft assembly
    • Removal of the factory tailhousing assembly
    • Installation of the Novak shaft and then tailhousing
    • Installation of all above items in reverse

    The endplay of the shaft bearings is already factory pre-set, simplifying reassembly by the installer.

    Driveshaft length changes are required. Work with your driveline supplier to match the Novak companion flange and select the u-joint of your choice, e.g., 1310 or 1350 and conventional u-joint or CV (Constant Velocity a.k.a., double-Cardan).

    Dana Model 300 companion flange rear view
    The dual pattern companion flange can accept a variety of yoke flanges. Also pictured here is Novak's billet Dana transfer case pan.

    Speed Sensors

    Due to length considerations, the 300RX will not drive a conventional speedometer cable, and instead uses a Vehicle Speed Sensor (VSS) of your choice. These optional speed sensors are available in two styles of output signal: GM (variable reluctance) with two wires, or, the Chrysler/Jeep (digital switch) with three wires.

    The wire leads provided will need to be spliced into the existing speed signal wiring, be it a PCM or aftermarket electronic speedometer.

    Speed Sensor Choices
    Choose from three different speed sensor configurations: GM's 40 pulse per revolution inductive signal, Chrysler / Jeep's 3 pulse per revolution digital signal, or no sensor..

    Related Products


    Jeep speed sensor for Dana 300

    Sensor, vehicle speed (VSS), digital, 1/2-20 threads x 2-1/4”. Knurled end with three lead wires, #0168K-13112

    This sensor will produce a signal appropriate for Mopar Jeep speed sensors, circa 1992 -

    Speed sensor for Jeep

    , #0010-02C

    DESCRIPTION

    Dana 300 Rebuild Kit

    Gaskets & Rebuild Kits for Dana 300 Transfer Cases

    Replace the hard-working bearings and intermediate shaft of your Dana transfer case with one of these kits, all while sealing it up and getting your bearing endplay correct. See them and several other parts and kits here for your Dana 300.

    Dana 300 rear bearing cap

    Dana 300 front rear output bearing cap, #8131657-K

    This innovative bearing cap uses o-ring sealing around its perimeter and bolt holes, then shims the bearing internally, instead of the leaky, exposed stack-up shims. This is one way Novak builds its own leak-free Dana 300's in-house.

    Billet aluminum Dana transfer case pan

    Dana Transfer Case Deep Billet Pan #D328D

    A deep and rigid billet aluminum pan for your Dana 300 transfer case. More fluid capacity, better sealing and some anodized eye candy for your geartrain. Shallow version for better ground clearance also available here.

    Dana 300 Input Retainer Assembly

    Kit, shaft, input, bearing w/retainer, preassembled with proper bearing preload, #D300-ISK

    If you are uncomfortable setting up the input on your D300 or simply would like our stronger billet retainer and all new components pre-set for your transfer case, this is the perfect solution. This kit includes our billet D300 input retainer, new snap ring, bearing and seal all assembled to the included Dana 300 input shaft as part of the #453 kit.

    Dana 300 twin stick shifter

    Shifter kits, Dana 300 twin stick

    Shifter upgrades are frequently done with a transmission swap. See our options for shifters, boots and knobs for your Dana 300, here.


    Driveshafts

    Driveshaft length changes will be required.

    Ask your driveline source for one of the following mating flange parts when having your driveshaft made / modified:

    • 1310 Standard U-joint - Spicer #2-2-939
    • 1310 CV joint - Spicer #211229X
    • 1350 Standard U-joint - Spicer #3-2-1619
    • 1350 CV Joint - Spicer #212024X

    There are two available bolt patterns for your companion flange:

    • The threaded holes in the provided Novak drive flange are M12-1.75 pitch
    • The thru holes in the flange are for 1/2" fasteners

    Jeeps that require extensive travel or specialty-built driveshafts have this option available through several fabricators across the nation. These are normally specified after placement of the new transmission and measured at vehicle ride height. As the rear driveline gets shorter, it is often advantageous to us a Double Cardan or “CV style” rear shaft with the correct geometry at the axle to minimize vibrations and possible binding.

    Axles

    Use of factory axles is completely acceptable with this conversion. Axle upgrades are not necessary, but they may be chosen for reasons external to this transmission upgrade.

    Also See